High pressure gas storage cylinders are typically low diameter and tall cylindrical vessels. The cylinders normally stand on the bottom of the vessel in an upright position. The gas storage cylinder is charged or discharged through the top opening by means of a suitable gas valve assembly. Usually, the gas valve assembly will include a regulator so as to withdraw the gas at a desired pressure level since often the cylinder storage pressure level is too high for use purposes. Since the gas storage cylinder is a relatively tall vessel with a small base, it can be subject to tipping. Should such a vessel fall, it is possible that the top valve assembly could be subjected to mechanical damage and cause dangerous discharge of the gas contents. Since the gas is stored in the cylinder at high pressure, any inadvertent gas discharge could result in high exiting gas velocity which would tend to propel the vessel and possibly damage surrounding equipment or personnel. Accordingly, it is important that the top valve assembly be protected from damage when the cylinder is not in use. In addition, U.S. Department of Transportation regulations require valves to be protected when gas storage cylinders are used in the transportation of certain gases. Further, since the valve assembly must be operated to regulate gas charging and discharging, it is imperative that the valve be protected from weather to prevent undesirable corrosion and deterioration of the valve assembly. It is conventional practice to protect the valve assembly of a high pressure gas cylinder with a suitable protective valve cover that serves to prevent physical damage or exposure of the valve to the weather.
Generally, the valve cover is attached to the gas storage cylinder by screwing onto a threaded piece which is attached to the cylinder. However, such an arrangement has several drawbacks. First, it requires a number of turns of the valve cover to securely attach the valve cover to the threaded piece. This is clumsy and time consuming. Second, such an arrangement is subject to loosening, leading to a potentially dangerous situation. This is because gas storage cylinders are often moved by turning the cylinder while pushing or pulling it along a surface. Third, the threads can corrode or otherwise foul making it difficult to remove the valve cover.
Accordingly, it is an object of this invention to provide an improved valve cover for a gas storage cylinder.
It is another object of this invention to provide an improved valve cover for a gas storage cylinder which can be easily and quickly attached and removed from the gas storage cylinder.
It is an further object of this invention to provide an improved valve cover for a gas storage cylinder which cannot easily be inadvertently loosed during rolling of the cylinder along its base.